Nail machine, and a tool ring and fitting for securing holding jaws for such machine

ABSTRACT

A fitting for the tool ring in a nail machine, or a tool ring, said fitting having means for receiving and securing at least one holding jaw in the fitting, and a support face that enables the fitting to abut on a support face which is complementary to the support face of the fitting; and means for clamping the fitting onto the complementary support face; and wherein the fitting has at least one clamp face which is arranged opposite the support face; and wherein the means for clamping the fitting on the tool ring comprise a first element configured for abutment on the clamp face and past the support face and for engaging with an element on a tool ring included therefor.

This application is a 35 USC 371 of PCT/DK99/00691 filed Dec. 9, 1999.

The present invention relates to nail machines, and a roller ring and afitting for such nail machine.

For instance, EP patent No 414 670 discloses state of the art nailmachines for manufacturing elongate bodies with heads, such as nails,screws, tacks and other elongate bodies with heads, wherein the machinehas a cutting station for cutting off individual pieces of wire that aresubsequently received in a roller device that comprises a tool ring,said tool ring having an axis of rotation where about the tool ring canbe caused to rotate; an outer and an inner surface that faces away fromand towards, respectively, the axis of rotation of the tool ring, and asurface which is substantially perpendicular relative to the axis ofrotation; and wherein the tool ring further comprises a plurality ofholding jaws and means for positioning and securing the holding jaws ata mutual distance along the circumference of the tool ring; and whereineach holding jaw has a groove for receiving an elongate bodylongitudinally of said groove whereby the holding jaw is caused to serveas clamp jaw for securing and positioning the elongate body.

Hereby the holding jaw is able to contribute to securing the cut-offlength of wire in order to enable that a head is rolled there onto, theholding jaw being configured such that the head is rolled out in acavity configured on said holding tray.

The tool ring in these machines being configured for rotating about saidaxis of rotation, it is enabled that a continuous process isaccomplished in which a plurality of holding jaws sequentially pass thepoint where the lengths of wire are cut off to enable that each cut-offlength of wire is introduced into a holding jaw following which theholding jaw is displaced away from the cutting station and towards theroller station where the head is rolled onto the cut-off length of wire.Obviously, in order to achieve a high productivity for the machine suchmachines receive many lengths of wire per time unit, and thispresupposes that the tool ring rotates at a relatively high rate ofrotation. This means that it is extremely important that the individualholding jaws are very accurately situated along the circumference of thetool ring.

Besides, it is obvious that the holding jaws are secured effectively soas to prevent them from breaking loose and displacing in particularduring the rolling process.

In the prior art machine this problem has been solved in that the toolring is provided with a substantially cylindrical and radially inwardlyoriented surface on the tool ring; and wherein the inwardly orientedsurface is provided with a plurality of holding jaws and a correspondingnumber of wedge-shaped spacer blocks that are secured in firm abutmenton the inwardly oriented surface by means of one or more machine boltsthat are screwed into the tool ring. By this solution a holding jaw anda spacer block are thus alternatingly arranged until the entireabove-mentioned, inwardly oriented surface is covered with holding jawsand spacer blocks that abut on each other. When the spacer blocks aresubsequently clamped against the tool ring, the above-describedwedge-shape of the spacer blocks causes the holding jaws to be wedgedfirmly between the spacer blocks, and by loosening and securing,respectively, the individual spacer blocks it is possible to regulatethe mutual distance between the holding trays.

However, it is a problem in connection with this type of machine thatthe above-mentioned clamping process is very time-consuming, and that inpractice it can only be performed to standard by an operator havingconsiderable experience. Besides, provided a single block or holding jawis loosened, crushed or deformed during use of the machine, this mayentail that all the spacer blocks and holding jaws configured in thetool ring must subsequently be adjusted following attachment or securingof the loose or destroyed spacer block or holding tray.

Additionally, an alternative type of machine is known wherein the toolring comprises a plurality of apertures in which a corresponding numberof holding jaws can be configured that are each attached by means of awedge-shape sleeve that extends around each holding tray, and whereinmeans are configured for displacing the wedges-shaped sleeve downwardsinto the apertures configured in the tool ring in such a manner that theholding jaw is wedged firmly into the aperture along with thewedges-shaped @sleeve. It is a problem of such machines, however, thatthe clamping of the holding jaws into the tool ring can entaildeformations in the tool ring proper as a consequence of the wedging-inof the individual holding tray, which means that in this case, too, itis necessary to carry out a very accurate clamping of the individualholding tray, in order to ensure the best possible quality of themanufacture of the individual nails, screws, tacks and the like objects.

In the light of this, it is the object of the present invention toprovide a machine whereby said drawbacks are fully or partiallyremedied.

In accordance with the invention, this is obtained in that the means forpositioning and securing the holding jaws on the tool ring comprises aplurality of fittings that are removable from the tool ring, each ofsaid fittings having means for receiving and securing at least oneholding jaw in the fitting, and a support face that allows the fittingto abut on a support face that is complementary to the support face ofthe fitting, and which is configured on one of said surfaces on the toolring; and means for clamping the fitting on the tool ring and whereinthe fitting has at least one clamp surface which is opposite the supportface; and wherein the means for clamping the fitting on the tool ringcomprises a first element that abuts on the clamp face of the fittingand a second element that extends from the clamp face past the supportface and engages with the tool ring.

Hereby it is indeed ensured that the forces necessary to ensureeffective attachment of the individual jaws are, to the widest extentpossible, received within the separate fitting itself, and thattherefore these forces are not to a substantial extent transmitted asflexural forces to the tool ring.

Besides, the clamping itself and the mounting of the individual fittingsmake smaller requirements to the operator, since individual fittings andassociated holding jaws can be replaced individually without therebynecessitating adjustment of the remaining holding trays, and since smallvariations in the clamping force have only a marginal bearing on theflexing of the tool ring.

The support face on the fitting and the complementary support face onthe tool ring can, in a preferred embodiment of the invention, beconfigured such that—following mounting of the fitting on the toolring—the fitting extends completely outside the surface of the tool ringon which the fitting is mounted.

Additionally, the tool ring and the fitting can advantageously havecomplementary guide faces that ensure correct positioning of the fittingwhen being mounted on the tool ring.

In a preferred embodiment of a nail machine according to the invention,such machine comprises two tool rings arranged opposite each other insuch a manner that their respective axes of rotation intersect at ablunt angle so as to cause two opposed holding jaws on the two toolrings to be pressed against each other along only a part of theperiphery of the tool ring.

According to a particularly preferred embodiment of the inventionwhereby a particularly simple mounting of the individual fitting isobtained, the means for clamping the fittings onto the tool ringcomprise a number of machine bolts; and wherein mounting apertures areprovided at the complementary support faces on the tool ring, saidmounting apertures being configured with a view to introduction of amachine bolt for securing the fitting onto the tool ring; and whereinthe mounting aperture extends substantially perpendicular to thecomplementary support face on the tool ring. In this context the fittingadvantageously comprises mounting apertures for insertion of the machinebolt, said mounting apertures extending through the fitting andsubstantially perpendicular to the support face of the fitting, and isarranged such that they correspond to the mounting apertures on the toolring to allow a machine bolt to be inserted through each mountingaperture in the fitting, and into the corresponding mounting aperture onthe tool ring, whereby the support face of the fitting is urged towardsthe corresponding complementary support face on the tool ring followingmounting of the fitting thereon.

According to a further preferred embodiment of the invention, thefitting comprises at least two clamp faces that face each other, andmeans for shifting the two clamp faces towards each other in such amanner that a holding jaw can be clamped between the two clamp faces;and wherein the fitting is configured as a yoke with two legs and aspacer element that extends between the two legs; and wherein the clampfaces are situated at the end of each leg in such a manner that atractive force occurs in the spacer element upon clamping of a holdingjaw between the clamp faces.

In this context, the support face of the fitting can conveniently belocated on the spacer element.

Besides, the clamp faces can conveniently be situated on that side ofthe spacer element which is opposite the support face of the fitting,whereby the spacer element will—following mounting of the fitting—extendbetween the holding jaw and the complementary support face.

According to a preferred embodiment, the fitting is configured forreceiving only one holding tray, and at least one of the legs on thefitting extends across the spacer element at a distance there from; andthe mounting apertures comprise a mounting aperture for each leg, saidmounting aperture extending through the leg as well as the spacerelement whereby the leg that extends a distance from the spacer elementis pressed in a direction towards the spacer element by clamping of thefitting; and wherein the two clamp faces converge towards each other ina direction away from the spacer element, whereby the holding jaw isclamped firmly between the two clamp faces upon attachment of thefitting onto the tool ring.

According to an alternative embodiment the fitting can advantageously beconfigured for receiving two or more holding trays, and wherein thefitting comprises a number of loose clamp blocks that each has twooppositely oriented clamp faces, said loose clamp blocks beingconfigured such that they can be positioned between the legs on the yokein such a manner that, between the clamp blocks and between the clampblocks and the legs on the yoke, a holding jaw can be received andattached.

The invention will now be described in further detail in the followingand with reference to the drawings, wherein:

FIG. 1 is a perspective explanatory sketch showing a nail machine, whoseprinciple is known, provided with a tool ring;

FIG. 2 is a sketch illustrating a section of a first embodiment of atool ring with a fitting according to the invention, for a nail machineas shown in FIG. 1;

FIG. 3a is a top plan view of the fitting shown in FIG. 2;

FIG. 3b is a sectional view of the fitting shown in FIG. 3a, along theline A—A;

FIG. 3c is a lateral view of the fitting shown in FIGS. 3a and 3 b;

FIG. 3d is a sectional view of the fitting shown in FIGS. 3a, 3 b and c,seen in a sectional view along the line B—B;

FIG. 4a is a top plan view of an alternative embodiment of a fittingaccording to the present invention;

FIG. 4b is a sectional view of the fitting shown in FIG. 4a, seen in asectional view along the line A—A;

FIG. 4c is a lateral view of the fitting shown in FIGS. 4a and 4 b;

FIG. 4d is a sectional view of the fitting shown in FIGS. 4a, b and c,seen in a sectional view along the line B—B;

FIG. 5a is a top plan view of a second, alternative embodiment of afitting according to the present invention;

FIG. 5b is a sectional view of the fitting shown in FIG. 5a, seen in asectional view along the line A—A;

FIG. 5c is a lateral view of the fitting shown in FIGS. 5a and 5 b;

FIG. 5d is a sectional view of the fitting shown in FIGS. 5a, b and c,seen in a sectional view along the line B—B;

FIG. 6 is a top plan sketch of a section of a second embodiment of atool ring with a fitting according to the invention for a nail machineaccording to FIG. 1;

FIG. 7 is a sectional view sketching the tool ring shown in FIG. 6 withfitting, seen in a sectional view along the line A—A shown in FIG. 6;

FIG. 8 is a top plan sketch of a section of a third embodiment of a toolring with a fitting according to the invention for a nail machineaccording to FIG. 1; and

FIG. 9 is a sectional view sketching the tool ring shown in FIG. 8 withfitting, seen in a sectional view along the line A—A shown in FIG. 8.

Thus, FIG. 1 illustrates a nail machine 1 that comprises a stretchingstation 2, through which a metal wire 3 is pulled by means of anarrangement of drive rollers 4 from a not shown coil of wire, andwherein the metal wire 3 is straightened thereby and stretched to asubstantially completely straightened piece of wire. After the driverollers 4, the metal wire 3 is displaced to pass through a wire cutterconsisting of two rotating wire cutters 5, and from the rotating wirecutters 5 the pieces of wire 6 cut off from the wire 3 are inserted intoa tool ring 7 that rotates clockwise in the embodiment shown herein. Theindividual lengths of wire 6 can be locked and positioned by means of aroller 8 intended therefore whereby the lengths of wire 6 extend equaldistances towards the center of the tool ring. At the bottom-most areaof the tool ring, a roller 9 is arranged that is configured to cooperatewith the tool ring 7 to roll heads onto the individual lengths of wire6. Then the lengths of wire 6 provided with heads are conveyed on in thetool ring and upwards to the topmost part of the tool ring 7 where thelength of wire provided with head is let go by the tool ring and dropsonto a chute 10 whereby the length of wire is removed from the nailmachine.

The above-mentioned machine and its functionality are in principlecommonly known; and for that reason they are not subject tospecifications herein. However, the present invention specificallyrelates to the tool ring, of which there are usually two in such nailmachine, which two tool rings are arranged opposite each other in such amanner that they are able to rotate synchronously about their axes ofrotation that usually intersect in an blunt angle. Hereby it is enabledthat the individual cut-off lengths of wire 6 can be clamped between thetwo tool rings along a minor part of the periphery of the tool ringwhich is subject to a very high abutment pressure, whereby it is ensuredthat the piece of wire is firmly locked during the rolling procedureproper.

Along the periphery of the tool ring, a row of holding jaws is arrangedwherein the jaws are usually made of a very hard and wear-resistantmetal. Such holding jaws are provided with a groove for receiving andsecuring the individual lengths of wire 6, and besides the holding jawshave, at the groove, a cavity in which the length of wire is deformedplastically, in such a manner that the cavity defines the shape of theunderside of the head rolled onto the length of wire 6.

Thus, these holding jaws are exposed to very powerful forces and to ahigh degree subject to wear, and therefore they are, as mentioned above,made of a very hard and wear-resistant material. Due to the fact thatthe holding jaws must be able to seize and firmly lock the individualcut-off lengths of wire 6 with a very high degree of accuracy, it isvery important that the holding jaws are positioned correctly along theperiphery of the tool ring.

Thus, FIG. 2 is a sectional view of a tool ring 7 according to theinvention, said tool ring 7 being provided with a fitting 10 in which aholding jaw 11 is mounted. Besides, the figure also illustrates how apiece of wire 6 rests in the holding jaw 11, and that a seizingmechanism is arranged that comprises a fixated holding jaw 12 and amovable holding jaw 13 that can, by means of a spring-biased movementmechanism 14 and a cam 15 that is fixated relative to the frame of thenail machine, be moved for attachment and release of the piece of wire6.

According to the invention the fitting 10 is releasably mounted on thetool ring 7 by means of two bolts 16, and the fitting 10 and the holdingjaw 11 thereby form a roller surface 17, so as to ensure that theinnermost end 18 of the piece of wire 6 is, by means of the roller 9shown in FIG. 1, rolled across the roller surface 17.

Now, FIGS. 3a, b, c and d illustrate in detail the fitting 10 shown inFIG. 2 comprising the holding jaw having the fitting 10 mounted therein.As shown in this embodiment the fitting 10 is configured with asubstantially plane support face 19 which is, following mounting on thetool ring 7 shown in FIG. 2, in abutment on a complementarily configuredsupport face on the tool ring 7. Besides, the fitting 10 is configuredas a yoke that comprises a bottom portion 20 on which the support face19 is configured. Op top of the bottom part 20, the holding jaw 11 isarranged between two clamp faces 2 that are configured on a pair ofelastic legs 22 that extend to both sides of the holding trays, and isat its most distal end relative to the holding jaw secured to the bottompart 20 on the fitting 10. As will appear, apertures 23 are configuredfor insertion of bolts 16 as shown in FIG. 2, said bolts 16 therebycausing both that the fitting 10 can be attached to the tool ring 7, andthat the holding jaw 11 is clamped firmly in the fitting between the twoclamp faces 21 on the elastic legs 22.

It will appear that, due to the structure of the fitting 10, the fitting10 will, upon mounting thereof on the tool ring 7, transmit relativelysmall flexural forces to the tool ring 7.

Now, FIGS. 4a, b, c and d illustrate an alternative embodiment of afitting 30 for a tool ring according to the present invention, saidfitting 30 corresponding exactly to the one shown in FIGS. 3a, b, c andd; and therefore this figure uses essentially the same referencenumerals.

The fitting shown in FIGS. 4a, b, c and d, however, have the onedifference that one of the elastic legs shown in FIGS. 3a, b, c and d isconfigured to be inelastic as an integral part of the bottom portion 20whereby it is ensured that a more exact positioning of the holding jaw11 is obtained relative to the fitting 30.

Now, FIGS. 5a, b, c and d illustrate a further alternative embodiment ofa fitting 40 according to the present invention, said fitting 40distinguishing itself in being able to receive two holding jaws 11 inone and the same fitting. As shown, the fitting comprises two separateportions, a yoke-shaped bottom part 41 and a clamp block 42, but apartfrom that the fitting 40 corresponds to the ones shown in FIGS. 3a, b, cand d; and the fittings 10 and 30 shown in FIGS. 4a, b, c and d; thefitting 40 according to FIGS. 5a, b, c and d having a bottom portion 20with a support face 19 and apertures 23 for receiving bolts for clampingthe fitting firmly onto the tool ring 7 according to FIG. 2, andsimultaneously for firmly clamping the holding jaws 11 in the fitting40.

However, the yoke-shaped bottom part 41 is configured in such a mannerthat it forms two opposed clamp faces 43 that are fixated relative tothe yoke-shaped bottom part 41, and wherein the clamp block 42 withopposed clamp faces 44 can be placed between the two clamp faces 43 onthe yoke-shaped bottom part 41 in such a manner that each of the holdingjaws 11 is firmly wedged between the clamp faces 43 on the yoke-shapedbottom part 41 and the clamp faces 44 on the clamp block 42, when theclamp block is firmly clamped by means of the bolting aperture 23therein.

In this manner fittings can in principle be constructed that containthree and more holding jaws by establishment of a correspondingly largernumber of clamp blocks. The very fact that the a fitting as shown isused for two holding jaws alone means that a very good positioning ofthe individual holding jaws is accomplished since they will always bepositioned in stable abutment against the two permanent clamp faces 43on the yoke-shaped bottom part 41.

Obviously the above-mentioned embodiments of fittings are not limitingfor the liberty at which the fittings can be arranged on a tool ring.

Thus, FIGS. 6 and 7 illustrate an alternative positioning of theindividual fittings on the tool ring, where FIG. 6 shows a section of atool ring 46 provided with a fitting 45 and seen from above, from whereit will appear that the fitting is secured radially towards the insideof the tool ring. FIG. 7 illustrates the embodiment shown in FIG. 6,seen in a sectional view along the line A—A in FIG. 6, from where itwill appear that the fitting 45 has a support face 47 that abuts on thecomplementarily configured support face 48 on the tool ring 46, and issecured thereto by means of two bolts 49 as shown in FIG. 6. Hereby thebolts will, as shown in the preceding figures, both have the function ofclamping the fitting 45 to the tool ring, and securing the holding jaw11 in the fitting 45.

Now FIGS. 8 and 9 illustrate an alternative positioning of a fitting 50according to the invention on a tool ring 51. From here it will appearthat the fitting can be located and attached on surface of the tool ring51 that is oriented radially outwards relative to the tool ring center,by the fitting 50 having a support face that is clamped towards thecomplementarily configured support face 52 on the tool ring 51.

In the same manner as shown in the embodiment illustrated in FIG. 2, theembodiments shown in FIGS. 6 through 9 bring about the advantages that aconsiderable amount of the forces required for ensuring the holding jaw11 in the fitting 45,50 is received within the fitting 45,50 proper andthus only a marginal portion of these forces is transmitted to the toolring 46,51 proper.

It will appear from this that the present invention can be exercised ina wide variety of ways apart from the above disclosures, whilevariations in the location and configuration of the individual fittingsin accordance with the actual situation are perceivable.

What is claimed is:
 1. A nail machine for the manufacture of heads onelongate bodies, including nails and screws, said machine comprising atleast one tool ring having an axis of rotation about which the tool ringcan be caused to rotate, an outer and an inner surface that face awayfrom and towards, respectively, the axis of rotation of the tool ring,and a surface that is substantially perpendicular relative to the axisof rotation, and wherein the tool ring further comprises a plurality ofholding jaws and means for positioning and securing the holding jaws ata mutual distance along the circumference of the tool ring, and whereineach holding jaw has a groove for receiving an elongate bodylongitudinally of the groove, whereby the holding jaw serves as clampjaw for securing and positioning the elongate body, characterized inthat the means for positioning and securing the holding jaws on the toolring comprise a plurality of fittings that are releasable relative tothe tool ring, each of said fittings having means for receiving andsecuring at least one holding jaw in the fitting, and a support facethat allows the fitting to abut on a support face that is complementaryto the support face of the fitting and configured on one of saidsurfaces on the tool ring, and means for securing the fitting on thetool ring, and wherein the fitting has at least one clamp face which isopposite the support face, and wherein the means for clamping thefitting onto the tool ring comprises a first element configured forabutment on the clamp face of the fitting, and a second elementconfigured for extending from the clamp face and past the support faceand engage with an element on the tool ring configured therefor.
 2. Anail machine according to claim 1, characterized in that the supportface on the fitting and the complementary support face on the tool ringare configured such that the fitting will, following mounting of thefitting on the tool ring, extend completely outside that surface on thetool ring on which the fitting is mounted.
 3. A nail machine accordingto claim 1, characterized in that the tool ring and the fitting havecomplementary guide faces that ensure correct positioning of the fittingby mounting thereof on the tool ring.
 4. A nail machine according claim1, characterized in that the machine comprises two tool rings locatedopposite each other in such a manner that their respective axes ofrotation intersect at a blunt angle in such a manner that opposedholding jaws on the two tool rings are pressed against each other onlyalong a part of the tool ring peripheries.
 5. A fitting for use in amachine or a tool ring in accordance with claim 1, characterized in thatthe fitting has means for receiving and securing at least one holdingjaw in the fitting, and a support face that allows the fitting to abuton a support face which is complementary to the support face of thefitting, and means for clamping the fitting to the complementary supportface; and wherein the fitting has at least one clamp face which isopposite the support face; and wherein the means for clamping thefitting on the tool ring comprise a first element configured forabutment on the clamp face of the fitting, and a second elementconfigured for extending from the clamp face and past the support faceand for engaging with an element on a tool ring intended therefor.
 6. Afitting according to claim 5, characterized in that the fitting has toclamp faces that face towards each other; and that the fitting has meansfor displacing the two clamp faces towards each other in such a mannerthat a holding jaw can be firmly clamped between the two clamp faces;and wherein the fitting is configured as a yoke with two legs and aspacer element that extends between the two legs; and wherein the clampfaces are configured at the end of each their leg in such a manner thata tractive force is produced in the spacer element when a holding jaw isclamped between the clamp faces.
 7. A fitting according to claim 5,characterized in that the support face of the fitting is configured onthe spacer element.
 8. A fitting according to claim 6, characterized inthat the clamp faces are arranged on the side of the spacer elementwhich is situated opposed the support face of the fitting, whereby thespacer element will, following mounting of the fitting, extend betweenthe holding jaw and the complementary support face.
 9. A fittingaccording to claim 5, characterized in that the fitting has mountingapertures for conveyance of a machine bolt, said mounting aperturesextending through the fitting and substantially perpendicular to thesupport face of the fitting, and is arranged such that they correspondto the mounting apertures on the tool ring, thereby enabling that amachine bolt can be conveyed through each mounting aperture in thefitting and into the corresponding mounting aperture on the tool ring,so that the support face of the fitting is pressed against thecorresponding complementary support face on the tool ring followingmounting of the fitting thereon.
 10. A fitting according to claim 8,characterized in that the fitting is configured for receiving only oneholding tray; and in that the legs on the fitting extend across thespacer element at a distance there from; and in that the mountingapertures comprise one mounting aperture for each leg, said mountingaperture extending through the leg as well as the spacer element in sucha manner that the leg is pressed in a direction towards the spacerelement by clamping of the fitting; and wherein the two clamp facesconverge mutually in a direction away from the spacer element.
 11. Afitting according to claim 8, characterized in that the fitting isconfigured for receiving two or more holding trays; and that the fittingcomprises a number of loose clamp blocks that each has two clamp facesthat face away from each other, said loose clamp blocks being configuredsuch that they can be arranged between the legs on the yoke so as toenable that, between the clamp blocks and between the clamp blocks andthe legs of the yoke, a holding jaw can be received and clamped.
 12. Atool ring for securing preferably elongate bodies in a machine for themanufacture of heads on elongate bodies, including nails and screws,said tool ring having an axis of rotation about which the tool ring canbe caused to rotate, an outer and an inner surface that face away fromand towards the axis of rotation, and a surface which is substantiallyperpendicular relative to the axis of rotation, and wherein the toolring further comprises a plurality of holding trays, and means forpositioning and securing the holding jaws at a mutual distance along thetool ring periphery, and wherein each holding jaw has a groove forreceiving an elongate body longitudinally of the groove whereby theholding jaw serves as clamp jaw for securing and positioning theelongate body, characterized in that the means for positioning andsecuring the holding jaws on the tool ring comprise a plurality offittings that are releasable relative to the tool ring, said fittingseach having means for receiving and securing at least one holding jaw inthe fitting, and a support face that allows the fitting to abut on asupport face which is complementary relative to the support face of thefitting, and is configured on one of said surfaces on the tool ring, andmeans for clamping the fitting on the tool ring, and wherein the toolhas at least one clamp face which is opposite the support face, andwherein the means for clamping the fitting on the tool ring comprise afirst element configured for abutment on the clamp face of the fitting,and a second element configured for extending from the clamp face andpast the support face, and for engaging with a part of the tool ringintended therefor.
 13. A tool ring according to claim 12, characterizedin that the support face on the fitting and the complementary supportface on the tool ring is configured such that, following mounting of thefitting on the tool ring, the fitting extends completely outside thesurface on the tool ring on which the fitting is mounted.
 14. A toolring according to claim 12, characterized in that the tool ring and thefitting have complementary guide faces that ensure correct positioningof the fitting when being mounted on the tool ring.
 15. A tool ringaccording to claim 12, characterized in that mounting apertures areconfigured at the complementary support faces of the tool ring, saidmounting apertures being configured with a view to the introduction of amachine bolt for clamping the fitting on the tool ring; and wherein themounting aperture extends substantially perpendicular to thecomplementary support face on the tool ring.